Multiple Antiplatelet Agents Research Articles

Detail analysis of puncture site complications in neuro-endovascular therapy: A single-center analysis

ObjectivePuncture site complications in neuro-endovascular therapy, which represent a significant cause of morbidity, are often difficult to treat. Vascular closure devices have evolved in endovascular therapy. We analyzed risk factors for puncture site complications and examined the efficacy of hemostasis methods in neuro-endovascular therapy. MethodsThis retrospective, observational, single-center study was conducted from January 2021 to January 2023. We enrolled 202 puncture sites of patients who underwent neuro-endovascular therapy at Kawaguchi Municipal Medical Center and analyzed the complications requiring additional intervention. ResultsThere were 12 (5.94 %) puncture site complications. No patient had permanent puncture-related complications. Univariate analyses revealed that a higher risk of puncture site complications was significantly associated with multiple antiplatelet agents (p = 0.03), hypertension (p = 0.03), scheduled treatment (p < 0.01), higher activated clotting time (ACT) immediately before sheath removal (≥310 s, p < 0.01), and the non-use of Perclose (manual compression or Angio-seal, p < 0.01). Multivariate analyses revealed that puncture site complications were significantly higher in patients with an ACT immediately before sheath removal ≥ 310 s (HR: 10.4, 95 % CI: 2.45–44.15, p < 0.01), scheduled treatment (HR: 10.16, 95 % CI: 1.81–56.95, p < 0.01), and the non-use of Perclose (HR: 21.97, 95 % CI: 2.42–199.34, p < 0.01). ConclusionA higher ACT immediately before sheath removal was significantly associated with puncture site complications. Perclose is an efficient device, and it may reduce the risk of puncture site complications.

Physician Approaches to Antithrombotic Therapies for Recently Symptomatic Carotid Stenosis.

Whereas the beneficial effect of antiplatelet therapy for recurrent stroke prevention has been well established, uncertainties remain regarding the optimal antithrombotic regimen for recently symptomatic carotid stenosis. We sought to explore the approaches of stroke physicians to antithrombotic management of patients with symptomatic carotid stenosis. We employed a qualitative descriptive methodology to explore the decision-making approaches and opinions of physicians regarding antithrombotic regimens for symptomatic carotid stenosis. We conducted semi-structured interviews with a purposive sample of 22 stroke physicians (11 neurologists, 3 geriatricians, 5 interventional-neuroradiologists, and 3 neurosurgeons) from 16 centers on four continents to discuss symptomatic carotid stenosis management. We then conducted thematic analysis on the transcripts. Important themes revealed from our analysis included limitations of existing clinical trial evidence, competing surgeon versus neurologist/internist preferences, and the choice of antiplatelet therapy while awaiting revascularization. There was a greater concern for adverse events while using multiple antiplatelet agents (e.g., dual-antiplatelet therapy (DAPT)) in patients undergoing carotid endarterectomy compared to carotid artery stenting. Regional variations included more frequent use of single antiplatelet agents among European participants. Areas of uncertainty included antithrombotic management if already on an antiplatelet agent, implications of nonstenotic features of carotid disease, the role of newer antiplatelet agents or anticoagulants, platelet aggregation testing, and timing of DAPT. Our qualitative findings can help physicians critically examine the rationale underlying their own antithrombotic approaches to symptomatic carotid stenosis. Future clinical trials may wish to accommodate identified variations in practice patterns and areas of uncertainty to better inform clinical practice.

Cerebral Infarction with Diffuse and Severe Atherosclerosis of The Main Cerebral Artery and Recurrent Infarction Despite Multiple Antiplatelet Agents: Management for Acute Stroke Patients

The recent approval of prasugrel will expand the choice of medical treatment. Prasugrel, as a platelet inhibitor, was approved for the management of cardiovascular events (including stent thrombosis) in patients with acute coronary syndrome in 2009. In 2021, it was also approved for use in patients with ischemic stroke. However, there have been cases of patients showing resistance to medical treatment and, therefore, worsening symptoms. It is important to approach treatment while considering the next step. Physicians should be aware of medical treatment choices, including the use of antiplatelet drugs, as well as the appropriate timing to shift to surgical treatment when necessary. In this paper, clinical practice options and guidelines will be considered.

Cerebral Infarction with Diffuse and Severe Atherosclerosis of The Main Cerebral Artery and Recurrent Infarction Despite Multiple Antiplatelet Agents: Treatment Strategy for Patients with Recurrent Cerebral Infarction During Antiplatelet Therapy

In real-world settings, many patients experience single or multiple recurrences of non-cardiogenic cerebral infarction, which is mainly caused by arteriosclerosis. These patients are treated according to set guidelines. While antiplatelet therapy is the standard treatment for preventing recurrence, this therapy alone is insufficient for full prevention of recurrence. Combining the administration of antiplatelet agents with the management of risk factors for recurrent cerebral infarction can maximize the preventive effects of these drugs.

Multiple versus fewer antiplatelet agents for preventing early recurrence after ischaemic stroke or transient ischaemic attack.

Stroke is a leading cause of morbidity and mortality worldwide. Antiplatelet agents are considered to be the cornerstone for secondary prevention of stroke, but the role of using multiple antiplatelet agents early after stroke or transient ischaemic attack (TIA) to improve outcomes has not been established. To determine the effectiveness and safety of initiating, within 72 hours after an ischaemic stroke or TIA, multiple antiplatelet agents versus fewer antiplatelet agents to prevent stroke recurrence. The analysis explores the evidence for different drug combinations. We searched the Cochrane Stroke Group Trials Register (last searched 6 July 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 7 of 12, 2020) (last searched 6 July 2020), MEDLINE Ovid (from 1946 to 6 July 2020), Embase (1980 to 6 July 2020), ClinicalTrials.gov, and the WHO ICTRP. We also searched the reference lists of identified studies and reviews and used the Science Citation Index Cited Reference search for forward tracking of included studies. We selected all randomised controlled trials (RCTs) that compared the use of multiple versus fewer antiplatelet agents initiated within 72 hours after stroke or TIA. We extracted data from eligible studies for the primary outcomes of stroke recurrence and vascular death, and secondary outcomes of myocardial infarction; composite outcome of stroke, myocardial infarction, and vascular death; intracranial haemorrhage; extracranial haemorrhage; ischaemic stroke; death from all causes; and haemorrhagic stroke. We computed an estimate of treatment effect and performed a test for heterogeneity between trials. We analysed data on an intention-to-treat basis and assessed bias for all studies. We rated the certainty of the evidence using the GRADE approach. We included 15 RCTs with a total of 17,091 participants. Compared with fewer antiplatelet agents, multiple antiplatelet agents were associated with a significantly lower risk of stroke recurrence (5.78% versus 7.84%, risk ratio (RR) 0.73, 95% confidence interval (CI) 0.66 to 0.82; P < 0.001; moderate-certainty evidence) with no significant difference in vascular death (0.60% versus 0.66%, RR 0.98, 95% CI 0.66 to 1.45; P = 0.94; moderate-certainty evidence). There was a higher risk of intracranial haemorrhage (0.42% versus 0.21%, RR 1.92, 95% CI 1.05 to 3.50; P = 0.03; low-certainty evidence) and extracranial haemorrhage (6.38% versus 2.81%, RR 2.25, 95% CI 1.88 to 2.70; P < 0.001; high-certainty evidence) with multiple antiplatelet agents. On secondary analysis of dual versus single antiplatelet agent therapy, benefit for stroke recurrence (5.73% versus 8.06%, RR 0.71, 95% CI 0.62 to 0.80; P < 0.001; moderate-certainty evidence) was maintained as well as risk of extracranial haemorrhage (1.24% versus 0.40%, RR 3.08, 95% CI 1.74 to 5.46; P < 0.001; high-certainty evidence). The composite outcome of stroke, myocardial infarction, and vascular death (6.37% versus 8.77%, RR 0.72, 95% CI 0.64 to 0.82; P < 0.001; moderate-certainty evidence) and ischaemic stroke (6.30% versus 8.94%, RR 0.70, 95% CI 0.61 to 0.81; P < 0.001; high-certainty evidence) were significantly in favour of dual antiplatelet therapy, whilst the risk of intracranial haemorrhage became less significant (0.34% versus 0.21%, RR 1.53, 95% CI 0.76 to 3.06; P = 0.23; low-certainty evidence). Multiple antiplatelet agents are more effective in reducing stroke recurrence but increase the risk of haemorrhage compared to one antiplatelet agent. The benefit in reduction of stroke recurrence seems to outweigh the harm for dual antiplatelet agents initiated in the acute setting and continued for one month. There is lack of evidence regarding multiple versus multiple antiplatelet agents. Further studies are required in different populations to establish comprehensive safety profiles and long-term outcomes to establish duration of therapy.

Post-ERCP Bleeding in the Era of Multiple Antiplatelet Agents

Background/AimsThis study aimed to determine the risk of post-endoscopic retrograde cholangiopancreatography (post-ERCP) bleeding among patients taking antiplatelet agents (APAs), particularly in the era of multiple APAs.MethodsThe primary outcomes were the frequency, type, and severity of ERCP-related bleeding according to the use of APAs.ResultsThe frequencies of post-ERCP bleeding among the four different groups were 16 of 2,083 (0.8%) in the no drug group, 12 of 256 (4.7%) in the aspirin group, 3 of 48 (6.3%) in the single APA group, and 4 of 48 (8.3%) in the multiple APA group (p<0.001). In the univariate analysis, post-ERCP bleeding was associated with age, pull-type sphincterotomy, and APA and was inversely associated with balloon dilation of the biliary orifice. In the multivariate analysis, pull-type sphincterotomy (odds ratio [OR], 7.829; 95% confidence interval [CI], 1.411 to 43.453; p=0.019) and country (Korea: OR, 0.124; 95% CI, 0.042 to 0.361; p<0.001) were associated with post-ERCP bleeding.ConclusionsThe frequency of post-ERCP bleeding was statistically higher in patients on any APA within 6 days prior to ERCP. However, in the multivariate analysis, APA use was not associated with post-ERCP bleeding. Until a large, adequately powered study to detect differences is performed, caution is recommended when considering invasive procedures during ERCP in patients on APAs.

Does Antiplatelet Therapy Affect Outcomes of Patients Receiving Abdominal Laparoscopic Surgery? Lessons from more than 1,000 Laparoscopic Operations in a Single Tertiary Referral Hospital

The effect of antiplatelet therapy (APT) on surgical blood loss and perioperative complications in patients receiving abdominal laparoscopic surgery still remains unclear. A total of 1,075 consecutive patients undergoing abdominal laparoscopic surgery between 2005 and 2011 were reviewed. Our perioperative management protocol consisted of interruption of APT 1 week before surgery and early postoperative reinstitution in low thromboembolic risk patients (n = 160, iAPT group). Preoperative APT was maintained in patients with high thromboembolic risk or emergent situation (n = 52, cAPT group). Perioperative and outcomes variables of cAPT and iAPT groups, including bleeding and thromboembolic complications, were compared with those of patients without APT (non-APT group, n = 863). In this cohort, 715 basic and 360 advanced laparoscopic operations were included. No patient suffering excessive intraoperative bleeding due to continuation of APT was observed. There were 10 postoperative bleeding complications (0.9%) and 3 thromboembolic events (0.3%), but the surgery was free of both complications in the cAPT group. No significant differences were found between the groups in operative blood loss, blood transfusion rate, and the occurrence of bleeding and thromboembolic complications. Multivariable analyses showed that multiple antiplatelet agents (p = 0.015) and intraoperative blood transfusion (p = 0.046) were significant prognostic factors for postoperative bleeding complications. Increased thromboembolic complications were independently associated with high New York Heart Association class (p = 0.019) and history of cerebral infarction (p = 0.048), but not associated with APT use. Abdominal laparoscopic operations were successfully performed without any increase in severe complications in patients with APT compared with the non-APT group under our rigorous perioperative assessment and management. Maintenance of single APT should be considered in patients with high thromboembolic risk, even when an abdominal laparoscopic approach is considered.

Novel Anti-platelet Agents: Focus on Thrombin Receptor Antagonists

Platelets are the key in the pathogenesis of atherothrombotic disease such as acute coronary syndromes, stroke, and peripheral arterial disease. Current anti-platelet treatments are mainly based on inhibition of two important pathways of platelet activation: thromboxane A2 (TXA2) mediated (aspirin) and adenosine diphosphate (ADP)-P2Y12 receptor mediated (clopidogrel, prasugrel, and ticagrelor). Despite the dual anti-platelet therapy with aspirin and P2Y12 inhibitors have reduced ischemic events in patients with acute coronary syndromes (ACS), the rate of recurrent ischemic complication after ACS remains high. Combination of multiple anti-platelet agents is also associated with increased risk of bleeding. Thrombin is a potent platelet agonist and the increase of its activity has been reported in patients with ACS. Platelet effects of thrombin are mediated by protease-activated receptors (PAR), and PAR-1 is the most important receptor in human platelets. Two PAR-1 antagonists, vorapaxar and atopaxar, have undergone clinical investigation. In this review, we will describe the pharmacology of PAR-1 antagonists and will review and discuss results of randomized clinical trials with PAR-1 antagonists.

Multiple antiplatelet therapy contributes to the reversible high signal spots on diffusion-weighted imaging in elective coiling of unruptured cerebral aneurysm

Our aim was to systematically investigate radiographic characteristics and outcome of diffusion-weighted imaging (DWI) changes in the elective coiling of unruptured cerebral aneurysm with analyzing the correlation of antiplatelet therapy (APT). In a total of 34 consecutive patients with unruptured cerebral aneurysms initially treated by coiling without stent assist, 26 (76.5%) had DWI changes with 91 high signal spots within 24-48 h after the procedure. We recorded DWI parameters (location, volume, mean, and minimum values of the apparent diffusion coefficient: expressed as ADCAVE and ADCMIN) for each lesion, and evaluated its radiographic outcome on conventional MRI at follow-up (interval, 58.4 ± 37.2 days) in the modes of APT. All patients with DWI high spots had no clinical symptoms. There was a strong correlation between ADCAVE and ADCMIN (r = 0.82, p < 0.0001). The mean ADCAVE and rADCAVE were 0.74 ± 0.14 × 10(-3) mm(2)/s and 87 ± 10 %. DWI high spots were small with a mean volume of 0.13 ± 0.12 cm(3), ranging from 0.04 to 0.86 cm(3). A negative correlation was observed between the volume and values of ADCAVE (r = -0.48, p < 0.0001). The DWI volume was significantly larger in single APT than in multiple (0.15 ± 0.14 versus 0.10 ± 0.07 cm(3), p = 0.0091). The permanent signal change was more observed in single APT than in multiple (24.5% versus 5.2%, p = 0.02). DWI high spots after elective coiling were small without significant decrease of ADC, and do not correspond to brain infarction. Periprocedural use of multiple antiplatelet agents is expected to reduce the volume of thromboembolism and permanent tissue damages.

Su1292 Lower Adenoma Detection Rates in Afternoon Colonoscopies May Be Due to Rushing and Not Fatigue

( 5, 5-10, 11-15, 16-20, 20 yrs), average endoscopic procedures/week (10-20, 21-30, 31-40, 40). Reasons for holding or continuing and time duration these agents weld held prior to and after procedures. Endoscopists experience of any complications secondary to holding or continuing different anti-platelet agents was also queried. Questions on holding or continuing specific anti-platelets agents in-combinations prior to low or high risk endoscopic procedures. Results: 400 study questionnaires were distributed and 136 responses received (response rate: 34%). The majority (82%) were community GIs, 68% in 4160 yrs age group, 76% 10 yrs of experience, 87% performed 30 procedures/week. GIs experiencing acute ischemic event when held: aspirin 11% (12/110); dipyridamole 6% (6/105) and clopidogrel 30% (34/114). GIs witnessed significant GI bleeding when continued: aspirin 38% (43/112); dipyridamole 23% (24/103) and clopidogrel 63% (71/112). GIs decision to continue/hold anti-platelet agents during endoscopy was based on patients factors (37%, 50/136), their own experience (15%, 21/136), and only 47% (64/136) followed ASGE guidelines for certain high risk procedures. 17% of all respondents would stop all anti-platelet agents for any endoscopic procedure; aspirin or NSAIDS held for 3-5 days (58%), dipyridamole or clopidogrel for 5-7 days (56%) and following endoscopy restarted within 3-5 days with polypectomy (73%), esophageal dilation (70%), ERCP with sphincterotomy (87%) and EUS with FNA (84%). Endoscopists who performed endoscopic procedures while patients were on single or multiple antiplatelet agents are shown in the Table. Conclusions: Results from this survey highlight the wide variation in practice patterns for managing various antiplatelet agents’ during endoscopic procedures among gastroenterologists despite the availability of guidelines on this topic. More than 15% of the respondents would hold all anti-platelet agents prior to any endoscopic procedures. This highlights the need for better educational tools to assist practicing gastroenterologists on this topic.

Safety of Dental Extractions in Coronary Drug‐Eluting Stenting Patients Without Stopping Multiple Antiplatelet Agents

The risk of excessive bleeding prompts physicians to stop multiple antiplatelet agents before minor surgery, which puts coronary stenting patients at risk for adverse thrombotic events. We hypothesized that most dental extractions can be carried out safely without stopping multiple antiplatelet agents. All dental extraction patients who had undergone coronary stenting and who were also on oral multiple antiplatelet agents therapy were enrolled. One hundred patients underwent dental procedures without stopping antiplatelet agents. All wounds were sutured and followed up at 24 hours, 1 week, and 1 month after the procedure. There were 2233 patients who had not taken oral antiplatelet agents from a health promotion center and had teeth extracted by the same method. After performing propensity-score matching for the entire population, a total of 100 matched pairs of patients were created. The primary outcome was a composite of excessive intraextraction blood loss, transfusion, and rehospitalization for bleeding, and the secondary outcome was a composite of death, nonfatal myocardial infarction, target lesion revascularization, and stent thrombosis within 1 month after the procedure. There were 2 excessive intraextraction bleeding cases that continued at the extraction site for 4 and 5 hours, respectively, in the coronary stenting patients, and 1 excessive intraextraction bleeding case that continued for 3 hours in the control patients. There were no cases of transfusion, rehospitalization for bleeding, or major cardiovascular events for the 2 propensity-matched groups. We found that most dental extractions in coronary stenting patients can be carried out safely without stopping multiple antiplatelet agents.

The rationale and evidence for triple antiplatelet therapy in acute coronary syndromes

The platelet response to endothelial injury is central to the process of atherothrombosis, the pathophysiologic hallmark of acute coronary syndromes (ACS). Multiple antiplatelet agents have been developed to inhibit key components of this platelet activity. The use of two or more antiplatelet agents in patients with ACS reduces ischemic events but increases bleeding risk. Triple antiplatelet therapy utilizing aspirin, P2Y12 antagonists and glycoprotein IIb/IIIa inhibitors, remains indicated in select ACS populations. In ST-elevation myocardial infarction, triple antiplatelet therapy may be beneficial in subjects receiving percutaneous coronary intervention without adequate thienopyridine preloading and in those with large thrombus burden. In subjects with non-ST elevation ACS, triple antiplatelet therapy is reserved for those at highest ischemic risk (e.g., elevated troponin or refractory ischemia) and for those with thrombotic complications at the time of percutaneous coronary intervention. The focus of ...

Evaluating the need for a practical risk score to predict major bleeding in acute coronary syndromes

The incidence of recurrent adverse ischemic events and death after acute coronary syndromes (ACS): unstable angina, ST-segment elevation myocardial infarction [STEMI] and non-STEMI [NSTEMI]) has been significantly reduced by advances in antithrombotic therapy and invasive treatment strategies [1–4]. However, the use of multiple antiplatelet agents (i.e., aspirin, P2Y12 inhibitors, and glycoprotein IIb/IIIa inhibitors [GPIs]) and antithrombotic therapies (i.e., unfractionated heparin [UFH], lowmolecular weight heparin, factor-Xa inhibitors and direct thrombin inhibitors), in combination with an early invasive approach has increased the risk of bleeding. The incidence of hemorrhagic complications after treatment of ACS ranges from 1 to 10%, depending on differences in patient characteristics, antithrombotic therapies, timing of event reporting and bleeding definitions [5–8]. Despite this heterogeneity, numerous studies have demonstrated that bleeding is associated with an increased risk for both shortand long-term adverse outcomes [5,7–12]. Although the exact mechanisms causing this increased risk after bleeding complications are not fully understood, a number of factors are likely to contribute, such as the cessation of evidence-based therapies (i.e., antiplatelet agents, b-blockers and statins) in patients who bleed, adverse effects of blood transfusion, detrimental effects of acute anemia and a greater prevalence of comorbidities in patients who bleed. In contemporary practice, cardiologists have a wide variety of antiplatelet and antithrombin agents from which to choose. Each individual drug has a different profile of clinical efficacy (suppression of ischemic complications from the ACS event itself, or from the treatments subsequently required, most commonly percutaneous coronary intervention [PCI]) versus complications (principally bleeding). Large randomized clinical trials have demonstrated that treatment strategies that reduce bleeding while effectively suppressing ischemia are associated with improved survival in patients with ACS. The Organization to Assess Strategies in Acute Ischemic Syndromes (OASIS)-5 trial randomized 20,078 patients with non-STelevation ACS to the low-molecular weight heparin enoxaparin or the factor-Xa inhibitor fondaparinux [13]. Fondaparinux was noninferior to enoxaparin in terms of the primary end points of death, myocardial infarction or refractory ischemia at 9 days. Moreover, fondaparinux was associated with significantly reduced rates of major bleeding at 9 days (2.2 vs 4.1%; p < 0.01) and significantly reduced rates of mortality at 30 days (2.9 vs 3.5%; p = 0.02) and 6 months (5.8 vs 6.5%; p = 0.05). The Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONSAMI) trial randomized 3602 STEMI patients undergoing primary PCI to treatment with either UFH plus a GPI or the direct thrombin inhibitor bivalirudin. In HORIZONS-AMI, bivalirudin compared with UFH plus a GPI was associated with significantly reduced major bleeding (4.9 vs 8.3%; p < 0.01) at 30-day follow-up, and mortality at 30 days (2.1 vs 3.1%; p = 0.047) and 1 year (3.5 vs 4.8%; p = 0.04) [14,15].

New-onset atrial fibrillation and acute coronary syndrome

Despite advances in the diagnosis and management of acute coronary syndrome (ACS), atrial fibrillation (AF) remains a commonly encountered complication leading to adverse short- and long-term outcomes across the whole spectrum of ACS. At present, the underlying mechanisms of AF in myocardial ischemia remain incompletely understood. This article evaluates the incidence and trends of new-onset AF in ACS, its impact on ACS management and the associated prognostic significance in patients with acute ischemic heart disease. The safety and use of oral anticoagulation treatment in ACS patients on multiple antiplatelet agents are also explored. Further experimental and clinical studies are needed to improve current understanding and management of new-onset AF in ACS patients.

Antiplatelet and Anticoagulant Therapies in Acute Coronary Syndromes

The combination of aspirin and clopidogrel is the mainstay antiplatelet therapy for acute coronary syndromes (ACS). However, the dosing of aspirin, the dosing of clopidogrel, the timing of clopidogrel initiation as well as the duration of clopidogrel therapy remain controversial matters. Clopidogrel resistance is an emerging concept with potential clinical implications. In the era of clopidogrel and bivalirudin, the role of glycoprotein IIb/IIIa antagonists is being challenged, yet they are still indicated in a select high-risk population. Concerning anticoagulant use in ACS, newer agents, bivalirudin and fondaparinux, have improved outcomes in comparison to heparin in patients managed with an invasive or conservative strategy, respectively. Combining multiple antiplatelet agents and an anticoagulant is the standard of care for ACS.

Bleeding and transfusion in acute coronary syndromes: a shift in the paradigm

Acute coronary syndromes (ACS), with or without ST segment elevation, are a frequent complication of atherothrombosis and are responsible for a high number of hospitalisations and interventions; thus, they represent...

282: The DuraHeart™ Left Ventricular Assist System Requires Less Intensive Antocoagulation

There has been concern that rotary blood pumps (RBP) provoke thrombosis unless aggressive anticoagulation (AC) therapy with multiple antiplatelet agents (AP) controlled by a thrombelastogram in addition to coumadin and aspirin is applied. In some RBPs thrombolysis using recombinant plasminogen activator was required to resolve pump thrombosis. This aggressive therapy sometimes resulted in fatal hemorrhagic stroke (HS). Risk of stroke exponentially increases with age after 40–45 years. HS has a significantly higher mortality rate within 30 days for patients (pts) older than 45 years than ischemic stroke (IS).

ＣＥＡ術前血小板凝集能検査の有用性

Although antiplatelet therapy is usually continued throughout the perioperative period of carotid endarterectomy to reduce the risk of recurrent stroke and other cardiovascular events, individualization still has not been standardized. To evaluate the relationship between preoperative antiplatelet agents and platelet aggregability, we analyzed 42 patients who underwent carotid endarterectomy from August 2005 to May 2006 in our institute. Among the 42, 19 were treated with aspirin alone, 5 with ticlopidine alone, 2 with cilostazol alone, 12 with aspirin and ticlopidine, 3 with aspirin and cilostazol and 1 with aspirin, ticlopidine, and cilostazol. Platelet aggregation in response to platelet agonist was measured in platelet-rich plasma obtained from the brachial vein 2 days prior to surgery. 1 μM and 10 μM ADP, or 2 μg/ml and 5 μg/ml collagen were used as agonists. Aggregation in response to appropriate agonist was inhibited in 73% of the aspirin group and 80% of ticlopidine group. None of the cilostazol group showed effects on aggregability. Patients were divided into 2 groups according to their preoperative platelet aggregability: inhibited (n=3) or non-inhibited (n=39). Intraoperative blood loss was 169.0±23.3 g (144-190 g) or 45.5±31.2 g (9-164 g), respectively. Operation time was 221.7±53.5 min (160-255 min) or 147.3±20.6 min (115-205 min), respectively. The main reason for blood loss and prolonged operation time was oozing from connective tissue. Aggregability in older patients who received multiple antiplatelet agents tended to be inhibited excessively. Taken together, preoperative analysis of platelet aggregability could be useful to reduce the risk of perioperative complication.

Risk of bleeding and restenosis among chronic kidney disease patients undergoing percutaneous coronary intervention

Bleeding risk is increased in renal failure due to impaired platelet adhesiveness. Patients who undergo percutaneous coronary intervention (PCI) are given multiple antiplatelet agents that increase that risk. We retrospectively tested the hypothesis that chronic kidney disease (CKD) patients who undergo PCI are at higher risk of bleeding and restenosis (due to chronic inflammation) compared to patients with normal renal function. Patients who had PCI for non-ST elevation myocardial infarction or unstable angina between July 2001 and June 2003 (1,184 patients) were included in the study. All the patients were given periprocedural clopidogrel, aspirin and glycoprotein IIb/IIIa inhibitor if indicated, and then continued on clopidogrel and aspirin daily for 12 months. The patients were classified into 5 groups according to the CKD stage and followed-up for 12 months for development of major or minor bleeding, restenosis, length of hospital stay and survival. The incidence of major bleeding within the first month (3.4% in normal kidney function patients (Gp 1), 4.8% for CKD Stages 1 and 2 patients (Gp2), 5.2% for CKD Stage 3 patients (Gp3), 6.1% for CKD Stage 4 patients (Gp4) and 9.3% for CKD Stage 5 patients (Gp5), p = 0.001) and for minor bleeding (5.7% in Gp1, 6.5% for Gp2, 7.4% for Gp3, 9.2% for Gp4 and 11.3% for Gp5, p = 0.001) and the incidence of restenosis at one month (4.6% in Gp1, 5.3% for Gp2, 6.8% for Gp3, 7.3% for Gp4 and 9.6% for Gp5, p = 0.001) and 6 months (11.2% in Gp1, 13.5% for Gp2, 15.7% for Gp3, 16.4% for Gp4 and 19.7% for Gp5, p = 0.001) were higher with worsening CKD. Survival at one year was worse with worsening of the kidney function. Worsening of CKD is associated with progressively increased risk of minor and major bleeding, restenosis and death during and after PCI.

Letter Regarding Article by Markus et al, “Dual Antiplatelet Therapy With Clopidogrel and Aspirin in Symptomatic Cardiac Stenosis Evaluated Using Doppler Embolic Signal Detection: The Clopidogrel and Aspirin for Reducton of Emboli in Symptomatic Carotid Stenosis (CARESS) Trial”

Letter Regarding Article by Markus et al, “Dual Antiplatelet Therapy With Clopidogrel and Aspirin in Symptomatic Cardiac Stenosis Evaluated Using Doppler Embolic Signal Detection: The Clopidogrel and Aspirin for Reducton of Emboli in Symptomatic Carotid Stenosis (CARESS) Trial”